Agradecimientos:
This work has been supported by the Ministerio de Ciencia y Tecnología of Spain through Grants No. BFM2003-07749- C05-01, No. FIS2004-01001, and No. NAN2004-09087- C03-03 (A.S.) and by “Acciones Integradas Hispano- Alemanas” HA2004-0034-D/04/39957 and by the Junta Andalucía under the Project No. FQN-0207.

Resumen:

We extend our previous work on soliton ratchet devices L. Morales-Molina et al., Eur. Phys. J. B 37, 79
2004 to consider the joint effect of two ac forces including nonharmonic drivings, as proposed for particle
ratchets by Savele’v et al. Europhys. Lett.We extend our previous work on soliton ratchet devices L. Morales-Molina et al., Eur. Phys. J. B 37, 79
2004 to consider the joint effect of two ac forces including nonharmonic drivings, as proposed for particle
ratchets by Savele’v et al. Europhys. Lett. 67, 179 2004 ; Phys. Rev. E 70, 066109 2004 . Current reversals
due to the interplay between the phases, frequencies, and amplitudes of the harmonics are obtained. An analysis
of the effect of the damping coefficient on the dynamics is presented. We show that solitons give rise to
nontrivial differences in the phenomenology reported for particle systems that arise from their extended
character. A comparison with soliton ratchets in homogeneous systems with biharmonic forces is also presented.
This ratchet device may be an ideal candidate for Josephson junction ratchets with intrinsic large
damping.[+][-]